Risk groups and staging for neuroblastoma
Doctors group children with neuroblastoma into risk groups, according to their risk of the cancer coming back after treatment. The risk groups are called:
-
low risk
-
intermediate risk
-
high risk
The treatment your child has for their neuroblastoma depends on which risk group they are in. Doctors use the cancer stage as well as the child’s age and results of other tests to make a decision about treatment.
Staging neuroblastoma
The stage of a cancer tells you the size and whether it has spread. Doctors use the International Neuroblastoma Risk Group Staging System.
The INRGSS uses tests such as CT, MRI and mIBG scans, as well as blood tests and biopsies, to look at particular details of the cancer. Doctors use this staging system when your child is first diagnosed, before they start treatment.
These details help build up a picture of your child’s cancer. They help your child’s doctor know how difficult the neuroblastoma might be to treat. For example, whether the cancer is wrapped around an organ or large blood vessel. These details are called ‘image defined risk factors’ (IDRF).
International Neuroblastoma Risk Group Staging System (INRGSS)
L1 The tumour is in one area of the body and hasn’t spread anywhere. It is possible to remove the cancer completely with surgery.
L2 The tumour is in one area of the body, but has started to spread. Tests show at least one or more ‘image defined risk factors’. It is not possible to remove it with surgery safely.
M The tumour has spread to distant parts of the body from where it started.
MS The tumour has spread to either the skin, liver, bone marrow. And your child is less than 12 months old.
Neuroblastoma risk groups
Doctors take into account a number of different things when deciding on a risk group. It’s likely that as our understanding of neuroblastoma develops, doctors will add or take factors out, to keep the risk groups up to date.
Age
Children diagnosed with neuroblastoma when they are younger than 12 to 18 months are at lower risk.
What the tumour looks like under a microscope (histology)
Tumours that haven’t spread with more mature looking cells can be lower risk.
Genetic changes
A gene called 
controls cell growth. Some neuroblastoma tumours have too many of these genes. This means that the cells grow quickly and are less likely to mature. Tumours with too many MYCN genes are nearly always high risk.
Anaplastic lymphoma kinase (ALK) gene is another type of cancer gene (oncogene). If changes happen to the ALK gene it can cause neuroblastoma cells to grow and behave abnormally as cancer cells. Although having this gene change doesn’t affect the risk group your child is in, it does change the treatment they have if they have high risk disease.
Doctors also look at how much there is in the cells (DNA ploidy). Genes are made of DNA and they are grouped together to make . Changes in chromosomes and how much DNA there is in a cell can affect how well treatment works.
So depending on the type of change in the chromosomes, your child may need more treatment. Your doctor will talk this through with you.
Treatment by risk group
We have information on what treatment to expect depending on what risk group your child is in.
Remember this is only a guide, your doctor and specialist nurse will give you a clear individual treatment plan for your child. Ask them as many questions as you need about staging, risk groups and the science of neuroblastoma. It’s very complex and no one would expect you to understand it all straightaway.
